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A monitor and alerting system for your data
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Pysellus - A monitor and alerting system for your data

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Pysellus is a stream-based, monitoring and alerting service that runs automatic tests against your data.

What would I use this for?

  • Filtering, merging and cleaning your data.
  • Searching for schemas and information in large, real-time data streams.
  • Setting up automatic alerts, notifications and triggers that run whenever a match happens.


Pysellus is written in Python 3, so you will need to have it installed.

Additionally, if you want to install Pysellus with pip, you will need to have pip3 installed.


You can get Pysellus just by running:

$ pip3 install pysellus

Or you can go ahead and clone this repo, and install it (needs setuptools)

$ python3 install

Getting started

Pysellus works by running some user-defined tests against all elements in a data stream.

Let's get started by writing a very basic test:

input = stream([0, 1, 2, 3])

def is_positive(number):
    return number > 0

@failure >> terminal
@check 'all numbers should be positive':

Save this to a file, for example test.stl, and then run it with pysellus:

$ pysellus test.stl

This will print to the terminal:

Assert error: In all numbers should be positive, got: 0

In the previous example, you wrote your tests in STL, or Stream Testing Language. This is just a thin DSL layer over regular Python, and its usage is completely optional.

You can read about the full STL syntax in the official [documentation](./doc/STL\, or learn how to write your tests in [regular Python](./doc/Python\ Test\


Pysellus is installed as a command-line application. To use it, just call pysellus, passing either your test directory or file path.

$ pysellus [-d|--dir] /path/to/test/dir,
           [-f|--file] /path/to/test/file



Contributors are welcome. Please fork the repository and send a pull request to the master branch.

Additionally, you can read the Contributing file.


Pysellus is released under the MIT License. For more information, see the License

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